1. Field of the Invention
The present invention relates to a boat in which operation information of each of a plurality of boat propulsion units is assigned a device instance number and transmitted via a communication network, and the operation information is displayed in each of a plurality of gauge sections provided in correspondence with the respective boat propulsion units.
2. Description of the Related Art
A boat having one or more outboard motors is provided with gauge sections for displaying the navigation speed and remaining fuel amount, engine speed and engine temperature of outboard motors, and the like. In the related art, it is known to connect these plurality of boat gauge sections and outboard motors to each other via a communication network such as CAN (control area network), and to transmit various kinds of information via the communication network.
A boat of this type includes, for example, a plurality of outboard motors, and a plurality of gauge sections corresponding to the respective outboard motors. Different device instance numbers can be set with respect to individual outboard motors. The device instance numbers are assigned to the operation information of the respective outboard motors and can be transmitted to a communication network. On the other hand, by configuring the respective gauge sections so as to be capable of identifying and receiving the device instance numbers of the respective corresponding outboard motors, it is possible to transmit the operation information of the respective outboard motors to the corresponding gauge sections for display.
A method of setting different device numbers with respect to a plurality of units, for example, is described in connection with the system disclosed in Japanese Publication No. JP 2005-161906. In this system, for example, a plurality of ECUs corresponding to a plurality of outboard motors are each provided with a number setting section, and the same initial value is set with respect to the respective number setting sections in advance. Upon activating each outboard motor, if the device instance number of another outboard motor is not received via a communication network, the initial value is set as the device instance number of that outboard motor, while if the device instance number of another outboard motor is received via the communication network, a device instance number different from the received device instance number is set as the device instance number.
In this case, since the same number is set as the initial value, upon activating the second outboard motor onward, the same number will be received. Accordingly, in the number setting section corresponding to the next outboard motor, a different device instance number is set by moving up the number to the smallest value that does not overlap with the number of the previously activated outboard motor.
On the other hand, the respective gauge sections are configured so as to be capable of selecting small device instance numbers in the order of placement.
According to the system as described above, by activating the plurality of outboard motors in their placement order, device instance numbers that accord with the placement order can be set with respect to the outboard motors. Further, it is possible to set the device instance numbers of the corresponding outboard motors sequentially with respect to the corresponding gauge sections. Accordingly, there is no need to use a special jig or the like for setting the device instance numbers, and device instance numbers can be readily set in the arrangement order of the outboard motors in accordance with a standard such as NMEA with respect to a plurality of outboard motors or the like.
However, if device instance numbers are set in accordance with the placement order in this way, when the outboard motors are activated in an order different from the order of their placement, device instance numbers that are not in accord with the placement order are set to the respective outboard motors and gauge sections. Accordingly, the activation order of the outboard motors is specified, which makes the setting operation cumbersome.